Weather and Traffic

More dry Saharan air arrives — how will it affect this week’s weather?

Opposing forces are battling it out for control over this week’s weather.

More southwesterly winds are on the docket in Palm Beach, according to National Weather Service forecasters, and normally that spells another wet period for the southeast coast. But don’t look for anything drenching, forecasters say, because air over the Florida peninsula continues to be unseasonably dry.

In fact, another Saharan Air Layer is moving into the area today, and although that won’t shut down storms on the East Coast, it should limit them, forecasters in Miami said. The best rain chances for the coming week are on Tuesday and Saturday, they said.

Meanwhile, back at the statistics desk, the Palm Beach area had a good week precipitation-wise with a five-day rain total of 2.14 inches at Palm Beach International Airport. That’s 81 percent of the total rainfall recorded for July — which cut nicely into the monthly deficit. As of Saturday, the official shortfall has dwindled to 0.83 of an inch at PBIA.

The airport picked up another 0.06 of an inch Saturday, while the island enjoyed a little more potent shower and reported 0.28 of an inch.

Precipitation deficits remain throughout much of the southeastern coast, with a 1.96-inch shortfall in Miami; and a 2.35-inch shortfall in Fort Lauderdale.

(Credit: U.S. Drought Monitor)

In its report on Thursday, the U.S. Drought Monitor left conditions in South Florida pretty much unchanged. Palm Beach is still dealing with a Severe Drought, and those conditions spread into western Palm Beach County last week. Almost all of Palm Beach County is in Severe Drought, with the exception of the northwest corner, which has been designated in Moderate Drought or Abnormally Dry.

Coastal Broward County and Coastal Miami-Dade County are dealing with Extreme Drought, the agency said.

It will be interesting to see how last week’s 2.14-inch PBIA rainfall impacts the next drought analysis. Although the Drought Monitor releases its updates on Thursday, the report reflects conditions on the previous Tuesday, which means those conditions were designated just before the rain started to fall in South Florida.

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(Credit: NOAA)

TROPICS TALK: Invest 93L was taken off the table by the National Hurricane Center on Saturday, the first tagged disturbance of the season that failed to develop into a named storm. Remnants of it can still be seen on satellite approaching the Lesser Antilles, but it’s no longer being tracked by the NHC.

Wind shear — strong upper-level winds that tear at systems trying to develop — is outrageously high in the Atlantic near the northeastern Caribbean Sea and into the Caribbean itself, running at between 40-60 knots. Experts say that the maximum wind shear that a storm can survive or develop in is about 20-30 knots.

The western Caribbean is a different story, with areas of 10-20 knots of shear and an area southwest of Cuba with wind shear of just 5-10 knots.

There is nothing to indicate that the wind shear in what’s known as the Main Development Region of the Atlantic — from the eastern Caribbean east to Africa — is going to relax any time soon. That’s according to wind shear tendency maps published by the University of Wisconsin.

Wind shear in the Caribbean this season is running about twice as high as it was in 1997 — the year of the super El Niño — according to the NHC’s Eric Blake.